My Cloud Home: Improper Limitation of a Pathname to a Restricted Directory
CVE-2022-29837 is a high-severity improper limitation of a pathname to a restricted directory vulnerability in My Cloud Home from Western Digital, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists version 8.12.0-178 as the first without the flaw, so updating My Cloud Home to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.2% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update My Cloud Home to 8.12.0-178 or a later version.
- Update ibi to 8.12.0-178 or a later version.
- Update My Cloud Home Firmware to 8.12.0-178 or a later version.
- Read the advisory on westerndigital.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Western Digital | My Cloud Home | My Cloud Home up to, but not including, 8.12.0-178; My Cloud Home Duo up to, but not including, 8.12.0-178 | 8.12.0-178 |
| SanDisk | ibi | ibi up to, but not including, 8.12.0-178 | 8.12.0-178 |
| Westerndigital | My Cloud Home Firmware | before 8.12.0-178 | 8.12.0-178 |
| Westerndigital | My Cloud Home Duo Firmware | before 8.12.0-178 | 8.12.0-178 |
| Westerndigital | Sandisk Ibi Firmware | before 8.12.0-178 | 8.12.0-178 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 4.7 | Medium | CNA (wdc.com) |
| CVSS 3.1 | 7.8 | High | NVD |
Official description
A path traversal vulnerability was addressed in Western Digital My Cloud Home, My Cloud Home Duo and SanDisk ibi which could allow an attacker to initiate installation of custom ZIP packages and overwrite system files. This could potentially lead to a code execution.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Limitation of a Pathname to a Restricted Directory
The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.
How developers prevent this class of flaw
- For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
- Use an application firewall that can detect attacks against this weakness. It can be beneficial in cases in which the code cannot be fixed (because it is controlled by a third party), as an emergency prevention measure while more comprehensive software assurance measures are applied, or to provide defense in depth.
More Improper Limitation of a Pathname to a Restricted Directory vulnerabilities (CWE-22)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Other vulnerabilities in My Cloud Home
- 9.8 Critical severity
- 9.8 Critical severity
Recent Improper Limitation of a Pathname to a Restricted Directory vulnerabilities
- 7.5 High severity
- 8.1 High severity
- 7.5 High severity
- 8.8 High severity
- 7.5 High severity
- 9.8 Critical severity
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